Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) said: O Messenger of Allah! Which deed is the best? The narrator said: The Messenger of Allah (peace and blessings be upon him) put out his tongue and then placed his finger on it. Mu'adh (may Allah be pleased with him) said: Inna lillahi wa inna ilayhi raji'un (We belong to Allah and to Him we return), and said: O Messenger of Allah! Will we be taken to account for everything we say, and will it be written against us? The narrator said: The Messenger of Allah (peace and blessings be upon him) struck the shoulder of Mu'adh (may Allah be pleased with him) several times and said: "May your mother lose you, O son of Umm Mu'adh! Does anything throw people on their faces into the Fire of Hell except the harvests of their tongues?"
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17252